Supposing there's no air
resistance, horizontal velocity is constant, which makes it very easy to solve
for the amount of time that the rock was in the air.
Initial horizontal
velocity is: <span>
cos(30 degrees) * 12m/s = 10.3923m/s
15.5m / 10.3923m/s = 1.49s
So the rock was in the air for 1.49 seconds. </span>
<span>
Now that we know that, we can use the following kinematics
equation:
d = v i * t + 1/2 * a * t^2
Where d is the difference in y position, t is the time that
the rock was in the air, and a is the vertical acceleration: -9.80m/s^2. </span>
<span>
Initial vertical velocity is sin(30 degrees) * 12m/s = 6 m/s
So:
d = 6 * 1.49 + (1/2) * (-9.80) * (1.49)^2
d = 8.94 + -10.89</span>
d = -1.95<span>
<span>This means that the initial y position is 1.95 m higher than
where the rock lands. </span></span>
This question is incomplete, the complete question is;
The wings of some beetles have closely spaced parallel lines of melanin, causing the wing to act as a reflection grating. Suppose sunlight shines straight onto a beetle wing.
If the melanin lines on the wing are spaced 2.0 μm apart, what is the first-order diffraction angle for green light (λ = 550 nm)?
Answer:
the first-order diffraction angle for green light is 15.96°
Explanation:
Given the data in the question;
from diffraction theory;
nλ = dsin∅
where n is the diffraction order ( 1st order = 1 )
λ is the wavelength ( 550 nm = 550 × 10⁻⁹ m)
d is the grating spacing ( 2.0 μm = 2.0 × 10⁻⁶ m )
∅ is the diffraction angle ( ? )
so we substitute
nλ = dsin∅
sin∅ = nλ / d
sin∅ = (1 × 550 × 10⁻⁹ m) / 2.0 × 10⁻⁶ m
sin∅ = 0.275
∅ = sin⁻¹(0.275)
∅ = 15.96°
Therefore, the first-order diffraction angle for green light is 15.96°
Answer:
Explanation:
Given that
Force is acting in the positive x direction,
Then F = 12.5 •i
The displacement is given as
d = 6 •i — 8 •j
Then,
Work done?
Work done is given as the dot product of force and displacement
W = F•d
W = 12.5i •(6i — 8j)
Note that,
i•i = j•j = 1
i•j = j•i = 0
Then,
W = (12.5×6)(i•i) —(12.5×8)(i•j)
W = 75 —0
W = 75J
work is done by the given force during this displacement is 75J
Electronic configuration of Nitrogen atom is,
[N] = 1s², 2s², 2p³.
Nitrogen has three electrons in its valence orbit. Therefore, it needs 3 more electrons to form stable octet or chemically stable.
